Hoist



H. N. KEENER Feb. 6, 1962 HOIST 2 Sheets-Sheet 1 Filed March 18, 1959/-/0w0/-0 /V/ c/90/J /(e anew INVENTOR.

ATTORNEY H. N. KEENER Feb. 6, 1962 HOIST 2 SheetsSheet 2 Filed March 18,1959 INVENTOR.

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My present invention relates to a lifting and lowering hoist which isparticularly adapted for use on a vehicle to accomplish loading andunloading thereof.

The problem of providing a hoist on a load-carrying vehicle such as atruck involves several design considerations. Initially, it is necessarythat such device he relatively compact in order to accommodate itselfwithin the outside dimensions of the truck body. In other words, thehoist should be of such SiZe when not in use as not to rise above thecab height or extend beyond the outside of the vehicle and interferewith its passage through restricted openings.

Secondly, the height of the truck bed above the ground and the maximumsize of the objects to be lifted necessitate a sufiicient range oftravel of the lifting means to permit its lowering to the ground and itsraising to a sufiicient height above the truck bed to allow the load tobe swung inboard.

In addition to these basic considerations, there are a number of otherfeatures which are desirable for greater safety or case of operation.Simple and rugged design, and mechanical means to aid in handling a loadand swinging the boom are examples of such features.

A hoist which answers all of the foregoing needs is ditiicult. todesign, particularly for use on vehicles which are of relatively smalldimension from the truck bed to the top of the cab, for example, apick-up truck. The problem is further complicated by the limitations ofconventional sources of power. A hydraulic hoist which eifects liftingand lowering by means of pressure fluid directed to a cylinder andmoving piston'does not lend itself tothe range of travel which isrequired. Further, experience has proven that it is virtually impossibleto maintain a closed hydraulic system free of leakage over a period oftime.

A winch driven cable assembly has been utilized for load handlingpurposes in a truck-mounted hoist, but it presents its own peculiarproblems, in that a drum must be provided on which to store the excesscable, and the placement of this somewhat bulky item at a convenientlocation for proper operation and safety of the operator is difiicult ofaccomplishment.

The foregoing discussion establishes the background which ledto myinvention, one of its primary objects being to provide a truck-mountedhoist which is of proper size to be conveniently accommodated on thework bed of aload-carrying vehicle and which may be adjusted totheproper configuration to accomplish any load handling assignmentconsistent with the capacity of the vehicle.

It is also an object of my invention to provide a hoist which is readilyextensible both upwardly and outwardly to -produce flexibility withregard to size ofloadand range of travel of the lifting and loweringmeans.

It is also an object of my invention to provide atruckmounted hoist inwhich a sprocket driven roller chain is employed as the moving elementfor lifting and lowering loads, thereby .overcomingthe objectionablefeatures of either hydraulic cylinders or winch and cable assemblies.

It is a further object of my invention to provide a truck-mounted hoistin which: the roller chain is carried s" a fight Fetter-steel Felt. a,ram

within the hoist itself, that portion of the chain which is not in useat any given moment being stored therein, whereby the unit is made safefor the operator, simple in design, andconvenient to operate.

It is a further object of my invention to provide a truck-mounted hoistwhich includes mechanical means for producing rotation thereof about avertical axis whereby the hoist boom can be swung inboard or outboard.

It is a further object of my invention to provide a hoist which may bemounted readily at any location either in or adjacent to the load bed ofa vehicle.

It is also an object of my invention to provide a truckmounted hoistwhich is simple and economical in construction and sufficiently ruggedto perform without malfunction under prolonged conditions of severe use.

The foregoing and other objects of my invention which shall becomeapparent are accomplished by means of a hoist unit comprising astationary base on which is rotatably mounted a hollow vertical member.A longitudinaily extensible boom is mounted atop the vertical member andis rotatable in a vertical plane about the pivot by which it is securedthereto. An extensible knee brace interconnects the vertical member andthe boom and supports the boom in any of several predetermined anglesrelative tov the horizontal as the boom is moved about its pivotalmounting. The moving element of the hoist which accomplishes the loadhandling function is a conventional roller chain having load attachingmeans such as a hook at one end thereof. The chain extends from thehook, over a free sprocket at the outboard end of the boom, within theboom to a worm and worm gear driven sprocket at the inboard end of theboom, and thence downward into the hollow interior of the verticalmember where that portion of the chain which is not in use convenientlynests atop itself. An additional feature is provided by a worm mountedon the stationary base of the hoist which coacts with worm gear teethatiixed about the periphery of the verticalmember to produce controlledrotation thereof about a vertical axis as theworm is driven by a crankhandle attached thereto.

The presently preferred form of my invention is illustrated in theattached drawings in which:

FIG. 1 is an elevation of my hoist mounted on the bed of a pick-uptruck;

FIG. Zis a plan view. of the installation shown in FIG. 1;

FIG. 3 is an elevation of an alternate installation;

FIG. 4 is an enlarged elevation of my hoist in partial section;

FIG. 5 is a section along line 55 of FIG. 4;

FIG. 6 is a section along line 6--6 of FIGA; and

FIG. 7 is a view in section of the load handling hook.

Referring now to FIGS. 1 and 2, reference number 10 designates thepick-up truck on which my hoist, indicated generally as 11, is mounted.A load W is suspended by the hook 12 on the terminal end of roller chain13, and the path of travel of the chain is inward along theboom 14 anddownward into vertical member 15. Knee brace 16 interconnects the twolast named elements and the vertical member 15 is rotatably mounted onthe base member 17. .The hoist operating means for moving in and payingout the chain are shown as 18, and the boom swinging means connectingthe base member 17 and'the vertical member 15 is designated by thenumeral 19.

In FIG. 3, the hoist is mountedoutside the confines of the truck bed,but within the limits defined by the outermost extension of the truckfender. This installation is equally satisfactory and has the addedadvantage of prea serving the entire bed of the truck for pay load. Itis apparent that in each of these installations, the base member 17 isattached to the frame of the truck in such manner as to react the loadson the hoist.

The dotted lines in FIG. 1 indicate an alternate configuration of thehoist in which the extensible features of the boom 14 and knee brace 16are illustrated. The means of effecting such change shall be describedin subsequent paragraphs.

FIGS. 4 through 7 illustrate the details of the design of the hoist. InFIG. 4, the boom 14 comprises an outer member 26 and an inner member 21which is slidable therein to produce extension of the boom as desired.The outer and inner members are provided with matching transverse holes22 to mark the predetermined increments of extension. In FiG. 4, theboom is in one of its intermediate positions, and the pin 23 extendsthrough one set of holes to maintain such configuration.

The knee brace 16 is similar in design to the boom, having an outermember 2 an inner member 25, a series of holes 26, and a locking pin 27to define its various positions. In FIG. 4, the knee brace is in aretracted for foreshortened position.

The vertical member is a hollow cylinder which is closed at the bottomby plate 23. At its top are two upwardly extending lugs 29, shown inFIG. 1, between which the boom 14 is accommodated. Pin 3d interconnectsthe lugs 29 and the boom to provide a horizontal axis about which theboom rotates to any of several attitudes for more advantageous approachto load handling problems.

The knee brace 16 is connected to the outer member of boom 14 by pin 31which extends between matching lugs 32 on the bottom thereof and the endof inner member 24, and is similarly connected to the vertical member 15by pin 34 extending between lugs 35 thereon and the end of outer member25. When it is desired to lift the boom, the pin 27 is withdrawn fromouter and inner members 24 and 25, and the knee brace is lengthened bysliding the inner member outwardly relative to the outer member, afterwhich the pin 27 is repositioned through the appropriate hole 26 to lockthe brace in its extended position. It is apparent that extension of thebrace will rotate the boom about pin 39 into a new position, i.e., agreater vertical angle relative to the axis of the vertical member 15.

At the outboard end of inner member 21 of boom 14 is a sprocket 4%carried by the shaft 41 which is journaled into the walls of member 21for rotation relative thereto. At the opposite or inboard end of boom 14is the hoist operating means 18 comprising in part a driven sprocket 42mounted on shaft 43 which is journaled within the walls of outer member20. The details of this assembly shall be described in subsequentparagraphs.

Within the outer member 26 of boom 14 immediately above the upper end ofvertical member 15 is the chain guide 44 and 44a which is adapted todirect the chain 13 about the sprocket 42 and downward into the hollowbore 45 of vertical member 15 which constitutes a chain storage chamber.The chain guide 44 is adapted to hold the chain 13 in position about thesprocket 42 over approximately five-sixths of its circumference.

The vertical member 15 is rotatably mounted within base member 17, adual section assembly comprising an upper hollow cylinder 46 having anoutturned flange 47 around the bottom thereof and a lower hollowcylinder 48 having an outturned flange 42 around the top thereof.Flanges 47 and 49 are substantially coextensive and bear against the topand bottom respectively of the bed 50 of the vehicle, in which positionthey are maintained by bolts 51 passing therethrough. .The bed 56 isdrilled to define a part of the continuous cylindrical bore throughmembers -46 and 48 which surrounds the lower portion of vertical member15.

The bottom of member 48 is closed by a plate 2 and aka a ball 53 betweenplates 28 and 52 allows rotation of the vertical member 15 thereabout.The inside diameters of members as and 48 are somewhat greater than theoutside diameter of the vertical member to accommodate a frictionreducing bearing or bearing surface 54 within the upper part of member46 and spacing lugs 55 within the lower part of member 48, the two lastdescribed elements serving to reduce rotational friction and maintainthe vertical member 15 and base member 17 in coaxial relationship.

The lower section 48 of the base member is attached to the frame of thevehicle in any convenient manner, as for example, the bracket 55 held byU bolts 57 about the channel member 58 which forms a part of thechassis.

It is apparent that rotation of the vertical member swings the boom, andmechanical means 1? are provided to simplify this operation andeliminate danger to the operator in attempting to accomplish it bydirect force on the load or boom. The details of the boom swinging meansshall be described in subsequent paragraphs.

Referring now to FIG. 5, the shaft 4-3 extends through the outer member20 of the boom 1-4 and bearings 60 and 61 allow rotation thereof. Thesprocket 42 is secured to the shaft 43 by key 62 and a worm gear 63 issecured to the end of shaft 43 which extends outside the outer member2%? by a key 64. A housing 65 is mounted atop the outer member 2% bymeans of a lug 66 welded to the housing and bolts 67 which mate withtapped. recesses in the outer member. Rotatably mounted within thehousing is a worm 68 which engages the worm gear 63 to produce rotationthereof when the worm is driven. For such purpose a crank handle 69 issecured to the end of the worm as shown in FIGS. 1 and 4; however, itwill be apparent that motor driven means could be substituted for thecrank handle as desired.

Experience has indicated that in certain installations it may bedesirable to provide positive locking means on the hoist operating means13 to prevent reverse operation when a load is suspended from the hoist.This can be accomplished readily with a ratchet wheel on worm as and alocking pawl on the housing 65, outer member 20 of the boom 14, or lug66. Such ratchet and pawl obviously would be adapted to allow rotationof the worm in a direction tending to reel in the chain and to preventrotation in the opposite direction. When the services of the lockingmeans are not required, the pawl can be rotated out of the engagementwith the ratchet wheel as is customary in an arrangement of this type.

FIG. 6 illustrates the arrangement of the boom swinging means 19. Acircle of worm gear teeth 71 are attached about the periphery ofvertical member 15 immediately above the point at which it emerges fromthe cylinder 46. Housing 72 is secured to the cylinder 46 by bracket 73,and the worm 74 within the housing engages the teeth 70. Worm 74 isattached. to shaft 75 which is rotatably mounted within the housing 72by bearings 76. Crank handle 77 and ratchet arm 78 are attached to shaft74 to produce rotation thereof. The handle and arm are shown at oppositeends of the shaft 75, but it is apparent that both could be mounted atthe same end and serve equally well. Rotation of the worm 74 by means ofeither of these members will rotate the vertical member within the basemember to swing the boom.

The provision of dual means for driving the worm is for the purpose offacilitating operation of the boom swinging means. The relatively shortcrank handle 77 may be used when there is no load on the hoist, at whichtime its lesser mechanical advantage would not pose a problem. Underload, the resistance of the boom to rotation might be increased to apoint where the crank handle could not readily perform its task. Undersuch circumstances the long ratchet arm 78 would be employed, it beingunderstood that a conventional ratchet assembly, well-known in the art,is incorporated into the arm at its point of attachment to the shaft 75so that in a selected direction of rotation, the ratchet pawl 79 ,willengage the ratchet teeth 79a on the shaft and drive it whereas when thearm is moved in the opposite direction, the pawl will fail to engage theteeth and thus the arm will rotate relative to the shaft intopositionforanew driving stroke.

The conventional roller chain employed in my winch cannot be rotatedabout its own axis to any great extent without damage. Thus the hook 12is provided with a swivel mounting whereby it may rotate above the axisof the chain. This arrangement is best shown in PEG. 7 in which theshank 80 of the hook extends into the lower portion of the swivelhousing 81, through the ball thrust bearing 82. A nut 83 is attachedabout the threads on the terminal end of the shank 80 and bears againstthe upper portion of the bearing 82. The chain receiving lug S4 isthreadably engaged within the upper portion of the housing 81, and theendmost link of the chain 13 is received within the apertures of thechain receiving lug and secured by pin 85. Thus the hook 13 may rotaterelative to the housing 81 on thrust bearing 82 and the chain is free toflex in a normal way about the pin 85.

The foregoing description relates to the presently preferred embodimentof my invention. However, it will be obvious to one skilled in the artthat it could be modified in several particulars without departing fromits spirit. Thus, I desire to protect by Letters Patent all forms of theinvention falling within the scope of the following claims:

1. A hoist comprising a base member, a vertical member rotatably mountedon said base member, a chain storage chamber within said verticalmember, a longitudinally extensible boom member pivotally mounted atopsaid vertical member for rotation about a horizontal axis, said boommember having an inboard and an outboard end and a sprocket chamberwithin said inboard end, boom locking means on said boom to maintainsaid boom member in the desired predetermined position of extension, alongitudinally extensible brace member interconnecting said verticalmember and said boom member at points intermediate their ends, bracelocking means on said brace member to maintain said brace member atvarious predetermined lengths to position said boom member at variousdesired angles relative to said vertical member, a first sprocketrotatably mounted at the outboard end of said boom member, a secondsprocket rotatably mounted within said sprocket chamber at said inboardend of said boom member, a worm and worm gear mounted on said boom andconnected to said second sprocket to produce rotation thereof, a rollerchain extending from said first sprocket along said boom member aroundsaid second sprocket and downward into said chain storage chamber withinsaid vertical member, and chain guide means mounted within said sprocketchamber of said boom member adjacent said second sprocket and projectinginto said chain storage chamber to hold said chain against said secondsprocket over a substantial portion of the circumference thereof andguide said chain into said storage chamber.

2. A hoist for use on the bed of a load carrying vehicle to accomplishloading and unloading thereof comprising a base member; a vertical boreextending into said base member; a vertical member carried within saidbore and extending upwardly therefrom; a chain storage chamberwithinsaid vertical member; a longitudinally extensible boom member pivotallymounted atop said vertical memher for rotation about a horizontal axis,said boom member comprising an outer member, an inner member carriedwithin and longitudinally slidable relative to said outer member, aspaced series of mating transverse bores through said outer and innermembers, and a pin removably insertable through said bores; alongitudinally extensible brace interconnecting said outer member ofsaid boom and said vertical member, said brace member comprising anouter member, an inner member carried within and longitudinally slidablerelative to said outer member, a spaced series of mating transverse.boresthrough said outer and inner members, and a pin removablyinsertable through said bores; afirst sprocket rotatably mounted at theoutboard end of said inner member of said boom member; a second sprocketrotatably mounted at the inboard end ofsaid outer member of said. boommember; a rotatable worm mounted on said boom member at said inboardend; a worm gear attached to said second sprocket and in operativeengagement with said Worm; a crank handle attached to said worm toproduce rotation thereof; a roller chain extending from a free end atthe outboard end of said boom member, around said first sprocket, withinsaid boom member, around said second sprocket, and downward into saidchain storage chamber within said vertical member; a chain guide withinsaid inboard end of said boom member projecting into said chain storagechamber to hold said chain in engagement with a substantial portion ofthe circumference of said second sprocket and guide it into said chainstorage chamber; load handling means attached to said free end of saidroller chain and axially rotatable relative thereto; and boom swingingmeans comprising a worm rotatably mounted on said base member, Worm gearteeth secured about the periphery of said vertical member in operativeengagement with said worm, and a handle attached to said worm to producerotation thereof.

3. The combination of claim 2 and a ratchet arm at tached to said wormof said boom swinging means to produce consecutive increments of rotarymovement thereof responsive to reciprocating rotation of said ratchetarm through a limited arc.

4. A hoist comprising a vertical member having a chain storage chambertherewithin, a hollow boom member mounted atop and extending outwardlyfrom said vertical member, a brace member interconnecting said verticalmember and said boom member, a first rotatable sprocket mounted at theoutboard end of said boom member, a second rotatable sprocket mountedwithin said boom member above said vertical member, driving meansconnected to said second sprocket to produce rotation there of, chainguide means adjacent said second sprocket and opening into said chainstorage chamber, and a roller chain extending from said first sprocketWithin said boom member around said second sprocket and through saidchain guide means into said chain storage chamber.

5. The combination of claim 4 in which said driving means comprises aworm and worm gear in operating relationship mounted on said boommember, and a handle attached to said worm to produce rotation thereof.

6. A hoist comprising a base member, a vertical member rotatably mountedon said base member, said vertical member having a chain storage chambertherewithin, a hollow boom member mounted atop and extending outwardlyfrom said vertical member, a brace member interconnectin g said verticalmember and said boom member, a first rotatable sprocket mounted at theoutboard end of said boom member, a second rotatable sprocket mountedWithin said boom member above said vertical member. driving meansconnected to said second sprocket to produce rotation thereof, chainguide means mounted within said boom member and projecting into saidchain storage chamber, a roller chain extending from said first sprocketalong said boom member around said second sprocket and through saidchain guide means into said chain storage chamber, and boom swingingmeans interconnecting said base member and said vertical member torotate the latter about its 'own axis.

7. The combination of claim 6 in which said boom swinging meanscomprises a worm rotatably mounted on said base member, matching wormgear teeth about the periphery of said vertical member, and meansattached to said worm to produce rotation thereof.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Moore Feb. 4, 1908 Foss Sept. 27, 1921 BakerNov. 3, 1925 Ashton Dec. 13, 1949 France Jan. 5, 1917 fla

